Exterior surface configuration of vehicular taillight



FIG. 1 is a perspective view of an exterior surface configuration of a vehicular taillight showing my present design;

FIG. 2 is a front view thereof;

FIG. 3 is a left view thereof; and,

FIG. 4 is a top plan view thereof.

The broken line showing of the vehicle portion is included for the purpose of illustrating only and forms no part of the claimed design. 

CLAIM I claim, the ornamental design for an exterior surface configuration of a vehicular taillight, as shown and described. 